This invention relates to the top burners of ranges and particularly to griddles and heat control thereof by means of a new and useful Gas Burner With Heat Reflective Radiants For Controlled Heat Concentration. Heretofore, griddle plates used in commercial kitchens have been fired by gas to one general heat level applied coextensively beneath the plate. In practice, there are situations where variation in heat level is desired at different areas of the griddle plate, and attempts at controlled variations in temperature have not been altogether successful. For example, conventional prior art burners have been installed beneath griddle plates in open communication with each other and sharing secondary burner air; so that the combined flames from a plurality of burners heats the griddle plate so generally that heat absorption thereto is inherently uniform and cannot be isolated to any degree of satisfaction. Therefore, to shut down one burner of a prior art griddle stove does not have the desired effect of appreciably reducing temperature in any selected area of the griddle, since the secondary burning of gases is distributed throughout an open combustion area coextensively beneath the griddle plate. It is a general object of this invention to isolate the effect of individually controllable burners and to separate combustion of each burner from the other. With the present invention selected areas of a griddle plate can be subjected to individual burner control.
Griddles of the type under consideration are heated by a plurality of underlying burners supplied with a primary air and gas mixture and operating in an open combustion chamber supplied with secondary combustion air. In the prior art griddle stoves the burners share a common combustion chamber beneath the griddle plate, and the distribution of heat is inherently general and uniform and in no sense isolated to any particular area of the griddle. It is an object of this invention to manifold combustion chambers and with each burner in a separate combustion chamber so that isolated operation of each burner is made possible. With the present invention, elongated burners are confined between walls sealed with the underside of the griddle plate, there being a plurality of burners and said complementary walls disposed in parallel relation with manifold combustion chambers established thereby and discharging into a common flue. It is, therefore, made possible to heat an area of the griddle plate overlying one or more burners and their complementary combustion chamber or chambers to a different top heat than that of an adjacent area of the griddle plate overlying another one or more burners and their complementary combustion chamber or chambers.
The prior art utilizes gas burners and radiants for the distribution of heat beneath griddle plates, but generally for uniform coextensive heat distribution, as distinguished from the isolation of distinct heat areas at different temperature. Consequently, prior art griddle stoves are characterized by open secondary combustion chambers without any suggestion of burner chamber separation. It is an object of this invention to seal off one chamber from the other and thereby manifolding the plurality of combustion chambers which discharge into and through a common flue. With the present invention, the griddle plate rests upon seals established by wall ridges coextensive with the burner combustion chambers.
Radiant heat and effective concentration of heat to the underside of the griddle plate is of economic concern, and it is an object of this invention to provide for controlled secondary air and flame support conductive to heat concentration and radiancy from reflective combustion chamber walls. With the present invention, the walls which complement the burners establish separate intake plenums for the supply of secondary air to opposite sides of the burner, and the walls also establish combustion chambers of upwardly divergent cross section so as to spread the generation of heat over a widened but restricted area of the griddle plate. The walls forming the combustion chamber are reflective heat absorbing radiants, and they efficiently direct heat to the overlying area of the griddle plate. A feature of this burner and combustion chamber combination is the concentration of heat from burner ports disposed at opposite sides of the elongated burner, at the transition plane between the secondary air intake plenum and the isolated combustion chamber sealed with the underside of the griddle plate.
Griddle plates are of heavy metal, a usual plate being one inch in thickness, and heat applied at the underside of the plate is conducted throughout the plate. Since it is the purpose of this invention to isolate distinct areas of the plate to operate at different temperatures, it is also an object of this invention to isolate areas of the plate per se, by restricting the conduction of heat from one area thereof to another. In practice, the body thickness of the plate is substantially reduced between adjoining areas of the plate, thereby isolating plate areas one from the other.